1. Field of the Invention
This application relates broadly to carton formation systems and methods. More particularly, it concerns machines and methods for setting up folded carton blanks and subsequently folding their minor and major flaps while gluing the major flaps to the minor flaps.
2. Description of the Prior Art
Foldable shipping cartons of the rectangular four-flap type are typically manufactured from a single piece of corrugated board or the like, cut into a predetermined pattern and provided with indented fold lines to enable the blank to be folded from a flat blank into a rectangular carton. The "knocked-down" flat carton blanks are shipped by the manufacturer to a user who must erect the blank by opening it into a tubular shape, fold the bottom flaps inwardly to a closed position and fasten them in the closed position e.g., by gluing, taping or stapling.
Numerous different types of machines have been developed for erecting carton blanks, then folding and fastening the flaps to form useable rectangular cartons. In some of such machines, the blanks are stacked in a vertical position for delivery into the machine, e.g., see U.S. Pat. Nos. 4,348,853; 4,579,551 and 4,892,513. In other machines, the blanks are stacked in a slanted position from which they are moved either from the top of the stack or from the bottom, e.g., see U.S. Pat. No. 4,331,435, into the machine. In still other machines, the blanks a stacked in a horizontal position from which they are moved either from the top of the stack, e.g., see U.S. Pat. No. 4,133,254, or from the bottom into the machine. The machines of the present invention are of the type in which the blanks are stacked in a horizontal position and are moved from the bottom of the stack into the machine.